Stockholder's Equity (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Common Stock, Dividends, Per Share, Declared		$ 0.17	$ 0.17
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 4,385		$ 4,345
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (14)
Net earnings attributable to BorgWarner Inc.		160	$ 225
Net earnings attributable to the noncontrolling interest, net of tax		11	12
Other Comprehensive Income (Loss)		(1)	60
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	[1]	1	2
Common Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		3	3	3		$ 3
Additional Paid-in Capital [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		1,111	1,102	1,146		1,118
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures		(10)	(1)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures		(25)	(15)
Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(1,626)	(1,486)	(1,585)		(1,445)
Treasury Stock, Value, Acquired, Cost Method		69	57
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		5,461	4,736	5,336		4,531
Dividends, Common Stock, Cash		(35)	(36)
Cumulative Effect of New Accounting Principle in Period of Adoption					16
Net earnings attributable to BorgWarner Inc.		160	225
AOCI Attributable to Parent [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(675)	(444)	(674)		(490)
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (14)
Other Comprehensive Income (Loss)		(1)	60
Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		111	105	$ 119		$ 109
Dividends, Common Stock, Cash		(20)	(18)
Net earnings attributable to the noncontrolling interest, net of tax		11	12
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		1	2
Performance Shares [Member] | Treasury Stock [Member]
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures		7	4
Restricted Stock [Member] | Treasury Stock [Member]
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures		$ 21	$ 12

[1] Net of income taxes.